Great cameras. I have three of them and use them as my primary travel cameras. The standard Industar-22 collapsible lens (50 mm f 3.5) is very sharp. You might also want to look at a Zorki-C or a Zorki-2C. The bodies on these are a bit taller in order to house the flash synchronization mechanism and some people say that they are not as attractive as the Zorki-1s, but they are otherwise mechanically equal and usually somewhat less expensive.

On ebay I have bought from alex-photo, asr-photo, and kubanoid. You could also buy from Oleg at www.okvintagecamera.com. He specializes in repair of cameras and does a CLA on everything he sells. In the US, you can also check with Yuri at www.fedka.com. He has all of his cameras CLAed in Russia.

If you want more information on these cameras and their relatives, there is a Russian camera forum on beststuff.com.